]>
Commit | Line | Data |
---|---|---|
42ce60aa | 1 | #!/usr/bin/env bash |
31cb50b5 MY |
2 | # SPDX-License-Identifier: GPL-2.0-only |
3 | # | |
4 | # Copyright (C) 2022 Masahiro Yamada <masahiroy@kernel.org> | |
5 | # | |
6 | # Exit with error if a local exported symbol is found. | |
7 | # EXPORT_SYMBOL should be used for global symbols. | |
8 | ||
9 | set -e | |
10 | ||
da4288b9 MY |
11 | # catch errors from ${NM} |
12 | set -o pipefail | |
13 | ||
14 | # Run the last element of a pipeline in the current shell. | |
15 | # Without this, the while-loop would be executed in a subshell, and | |
16 | # the changes made to 'symbol_types' and 'export_symbols' would be lost. | |
17 | shopt -s lastpipe | |
18 | ||
31cb50b5 MY |
19 | declare -A symbol_types |
20 | declare -a export_symbols | |
21 | ||
22 | exit_code=0 | |
23 | ||
da4288b9 MY |
24 | # If there is no symbol in the object, ${NM} (both GNU nm and llvm-nm) shows |
25 | # 'no symbols' diagnostic (but exits with 0). It is harmless and hidden by | |
26 | # '2>/dev/null'. However, it suppresses real error messages as well. Add a | |
27 | # hand-crafted error message here. | |
28 | # | |
29 | # TODO: | |
30 | # Use --quiet instead of 2>/dev/null when we upgrade the minimum version of | |
31 | # binutils to 2.37, llvm to 13.0.0. | |
32 | # Then, the following line will be really simple: | |
33 | # ${NM} --quiet ${1} | | |
34 | ||
35 | { ${NM} ${1} 2>/dev/null || { echo "${0}: ${NM} failed" >&2; false; } } | | |
31cb50b5 MY |
36 | while read value type name |
37 | do | |
38 | # Skip the line if the number of fields is less than 3. | |
39 | # | |
40 | # case 1) | |
41 | # For undefined symbols, the first field (value) is empty. | |
42 | # The outout looks like this: | |
43 | # " U _printk" | |
44 | # It is unneeded to record undefined symbols. | |
45 | # | |
46 | # case 2) | |
47 | # For Clang LTO, llvm-nm outputs a line with type 't' but empty name: | |
48 | # "---------------- t" | |
49 | if [[ -z ${name} ]]; then | |
50 | continue | |
51 | fi | |
52 | ||
53 | # save (name, type) in the associative array | |
54 | symbol_types[${name}]=${type} | |
55 | ||
56 | # append the exported symbol to the array | |
57 | if [[ ${name} == __ksymtab_* ]]; then | |
58 | export_symbols+=(${name#__ksymtab_}) | |
59 | fi | |
da4288b9 | 60 | done |
31cb50b5 MY |
61 | |
62 | for name in "${export_symbols[@]}" | |
63 | do | |
64 | # nm(3) says "If lowercase, the symbol is usually local" | |
65 | if [[ ${symbol_types[$name]} =~ [a-z] ]]; then | |
66 | echo "$@: error: local symbol '${name}' was exported" >&2 | |
67 | exit_code=1 | |
68 | fi | |
69 | done | |
70 | ||
71 | exit ${exit_code} |